Handicapped individuals frequently require assistance in areas such as communication, mobility, eating and play. This assistance is typically provided by persons such as therapists. Recent technological advances have resulted in communication devices and systems which give handicapped individuals a greater degree of independence and skill development than had heretofore been possible. Communication aids for nonverbal persons typically rely on the visual skills of the user for operation. One example of an early communication system was developed for use by nonverbal physically handicapped persons by C. K. Bliss in the 1930's. The Bliss system is based on a set of visual-pictorial symbols comprising four hundred symbols accompanied by appropriate English words, which are pointed to by the user. See Galliers, "A.I. For Special Needs-An "Intelligent" Communication Aid for Bliss Users", 1 Applied Artificial Intelligence 77 (1987). Frequently, however, such systems require visual or motor skills that are beyond the capability of the multi-handicapped individual. For example, a handicapped individual may not have the requisite motor skills to operate the computer keyboard required in some systems. In other cases, an individual may not have the requisite visual skills required to operate the system. For example, in some scanning systems the user watches a light or row scanning system until it reaches a specific spot, and the user must then activate a switch to operate speech output at that point. Persons with visual perceptual difficulties such as poor visual attending, visual tracking, visual scanning, etc. frequently have difficulties with these kinds of systems.
To overcome this problem, communication systems have been developed which do not rely on the visual skills of the user, but instead present information to the user auditorially. Such systems could then be used by persons with low visual functioning or even by blind persons. One system, known as the Audio Com, was developed by John Smallwood of the Communication Enhancement Resource Center of the Northwood Public Schools in Northville, Michigan. The Audio Com system utilized a Z80 single board microprocessor together with a Votrax "type and talk" system modified for battery operation. The Audio Com used a single switch input along with an earphone and an external speaker under the control of the software. Programming was done in BASIC. The user of the Audio Com could select words desired to be spoken from those stored in memory in the following way. The user would make momentary contact of a single switch which would cause the generation of a vocabulary category list from which the user could select a category he/she was interested in. These categories might be, for example, nouns, verbs, pre-stored phrases, and a selected number of subject categories, such as food, clothing, health care needs, or numbers. As this list of categories was being spoken by the Audio Com in the earphone, the user would actuate the switch for the category he wanted as that category was being spoken.
Next, the Audio Com would present entries from the selected category in sequential fashion allowing for a similar selection to be made by the user as the entry within the selected category was spoken. The Audio Com would then return to and repeat the category list so that another category selection could be made. This step of listing entries in the selected category was repeated again so that additional words or phrases could be selected. The selected entries were stored sequentially in a text buffer. This process was then repeated until a desired thought or message had been accumulated in the text buffer. To play out the text buffer upon completion of formation of the message, the user would hold a single switch closed for a longer than normal time (two or three times longer) such as 1.5 seconds. This put the Audio Com into a user command mode, at which time the speak function could be selected. In the command mode, the Audio Com would repeat a series of commands and the user would strike the switch at the time the desired command was heard. Commands being spoken included: backspace, clear and speak. The speak command spoke the text in the buffer, not through the user earphone, but through the external speaker so that another person could hear it. The Audio Com system also permitted the user to control relays which in turn provided single switch, on and off instructions to external devices. For example, four relay contacts would be used to move a wheelchair in four directions. Alternatively, the relays may be used to operate a Windsford automatic mechanical feeder, or other devices.
One disadvantage with systems such as the Audio Com is the length of time it takes for an individual to scan the required categories and list of words in order to construct useful phrases. Because of this limitation, programming the Audio Com resulted in a compromise between available vocabulary and speed. That is, as the potential vocabulary increases the number of categories and word choices must increase, and this slows down the phrase building task of the user. Phrase building can be streamlined by reducing the number of categories and words, however, this limits the available vocabulary. Thus, it would be desirable to provide a method for streamlining the process of constructing phrases without limiting the available vocabulary.
Another problem with the Audio Com system is that it is not easily adaptable to the particular needs and capabilities of the user. By the same token, the Audio Com system was not easy to upgrade to the increasing level of proficiency of particular users. This is because the software for the Audio Com system was written in BASIC and program changes could only be performed by persons with the necessary programming skills, and who also understood the systematic rules relative to the construction of words using phonemes for the Votrax speech system. As a result, therapists, who were in the best position to understand the individual needs of the user, were unable to adapt or customize these programs to particular users since they were typically neither computer programmers nor familiar with the nuances of generating suitable command words for driving a votrax speech synthesizer. Consequently, it would be desirable to have a communication system in which therapists and other non-programmers can easily change the categories and word choices to better match the abilities and interests of each individual user.
In light of the foregoing problems and needs, it is an object of the present invention to provide new methods and systems for enabling multi-handicapped nonverbal individuals to interact with persons and systems. It is another object of the present invention to provide methods and systems for single switch generation of synthetic speech and other communications in which sentences can be constructed in a quicker and more streamlined fashion without limiting the available vocabulary. It is a further object of the present invention to provide a communication system which is easily adapted to the individual needs and abilities of the user. Still another object of the present invention is to provide a communication system which utilizes a simplified programming method so that persons who are not computer programmers can modify the language capability of the system to match that of the user.